<template>
  <h2 @click="happy">{{count}}</h2>

  <!-- <h3 v-if="count < 30">我很开心</h3>
  <h3 v-else-if="count < 40">我不开心</h3>
  <h3 v-else>我很痛苦</h3> -->

  <h4 v-show="count < 30">我很开心</h4>

</template>

<script setup>
import { ref } from 'vue'

let count = ref(20)

const happy = () => {
  count.value++

}
</script>

<style lang="css" scoped>

</style>